This was the first of the Soviet Union's "third-generation" deep space planetary
probes of the 3MV series. Like the second generation, Soviet engineers projected four types of the 3MV: the 3MV-1 (for Venus impact), 3MV-2 (for Venus flyby), 3MV-3 (for Mars impact), and 3MV-4 (for Mars flyby). The primary difference over the second generation was vastly improved (and in many cases doubled) orientation system elements.

While these four versions were meant to study Mars and Venus, the Soviets conceived of two additional variants of the series, similar but not identical to the 3MV-1 and 3MV- 4 versions. These "test variants" were designed to verify key technological systems during simpler missions on flyby missions to the Moon and the near planets.

On this particular launch, the first to fly a "test variant," the third and fourth stages separated abnormally; after the craft reached Earth orbit, ground control lost telemetry from the Blok L upper stage designed to send the vehicle past
the Moon. The stage's main engine turbopump probably exploded upon ignition,
destroying the payload.

With this mission, the Soviets began the practice of giving Kosmos designations to lunar and planetary probes that remained stranded in Earth orbit.

Key Dates

11 Nov 1963: Launch

Status: Unsuccessful

Fast Facts

Beginning in 1963, the name Kosmos was given to Soviet spacecraft which remained in Earth orbit, regardless of whether that was their intended final destination. This was the first mission to get that designation.

Typically Soviet planetary missions were initially put into an Earth parking orbit as a launch platform with a rocket engine and attached probe.

If the engine misfired or the burn was not completed, the probes would be left in Earth orbit and given a Kosmos designation.